spectroscope

a spectrum

to use / to employ / to make use of, to apply / to spend

a spectrum

to divide light into a spectrum

(mathematics, chemistry) analysis

to analyze

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend